Thì QKĐ:

1.Some new pens were bought by Peter

2.The exercises were done by the students

3.This tree was watered by the woman

Thì QKTD:

1.The flowers were being cut

2.A letter was being written by her friend

3.The bike was being repaired by Mr John

IV: 1, Some new pitures were bought by Peter

2, The exercises were did by the students

3, This tree was watered by the woman

V: 1, The flowers were being cut down 

2, A letter was being written by her friend

3, The bike was being repaired by Mr.John

VI: 1, Some cakes had been made by Mary

2, The windows had been closed by us

3, Lan has been invited to the party by him